Who makes this air suspension system?

We have just bought a 50 merc that is in various stages of completion. We have no documentation on anything with this car and would like to get an owners manual for the air suspension so I can figure it out.
Does anyone know who makes this and/or how I can get a manual?
On the black box that encloses the compressor, the holes in it for the cooling fan has "PnP" on it.

Thanks in advance for any help,
BLR

 

http://www.airbagit.com/v/vspfiles/pages/PlugNPlay_PAGE.html


Pnp=plug-n-play

 

He's correct^